I am getting close to re-entry into the Coast Guard Aux Air program with my Twin Comanche (PA-30C), and have been told to expect long (3-4 hours) flights at 100KT airspeed. I'm estimating that will require running the engines (LYC IO-320-B1A) at 40% or lower power settings.

My question is: Is there a BEST way to configure the engine settings (MP vs RPM) for this type of operation? HIGH RPM and LOW MP, or the other way around?

My concern is that, when I flew for them before in a Mooney with a LYC IO-360-A1A, it lead to the engine burning lots of oil, and finally a Top Overhaul. I want to prevent that from happening again.

My personal opinion is you need a Cherokee 140 or just plan on overhauling the engines when you are done with this type of flying. You might call Lycoming for a second opinion.

Can't imagine flying my Twin that way.

They require a Twin for operations more than 25 miles from shore, and some SAR cases require that.

You might want to consider flying at partial flaps for a better deck angle. It would require higher power settings though.

Low RPM is best. Doing this occasionally is OK, but beware of increased oil consumption indicating that the cyl bores are glazed. About tho only way to fix is to pull cyl and hone. Running 3-4 hrs low power and then running it hard for a period of time to get the pressure and temps up (think breaking in cyl) will keep this from happening.

There must be volumes written on this. Didn't the Air Force get ultra long range with the P38 in the Pacific by running low power setting. I recall that Lindbergh was the one who taught them.

Clarence

Max Conrad is the guy who did Casablanca, Morocco to LA. I just don't know what he did on power settings. His 250 is at Liberal KS Museum. The pilot seat is a fuel tank.

Don't know how I missed this post back in Sept. Brought back some fond memories.
In 1961 I worked for a Piper dealer in southern Ill. On a Friday am I was told that I would meet a TWA flight at STL
to pick up a passenger and take the gentleman to a dealer dinner at Carbondale, Ill. and that I would be staying for the
dinner and talks by William T. and a surprise guest speaker.
I flew our PA-24-180 charter aircraft over to STL and was parked in a gate at the TWA terminal....boy were things loose and easy back then....as a TWA Connie parked in the gate just ahead of me. The deplaning steps in place, the passengers deplaned and one gentleman with a small carry-on was looking at me as he descended the steps. Reaching the ground he turned left and headed my direction. As he neared I realized it was Max Conrad.
MAX CONRAD!!!!!
I'm 21 with maybe 1000hrs. and I'm to fly Max Conrad to Carbondale? In a 180 Comanche?
After shaking hands the first thing I did was offer for him to fly. (PLEASE) He said no thanks and my lot was cast.
We boarded, fired up, taxied out, took off and headed southeast at 3500'. Radio chatter was busy and no time was
available for he and I to talk.
East of the Mississippi work load eased and he made a comment that I sure knew how to operate in a busy airport.
He had a talent for making those around him feel at ease and I sensed this immediately.
We had a nice visit enroute and I asked him what power settings he used on his record flights. He asked if he could show me and I said sure.
He pushed the throttle all the way in and pulled the prop control all the way back, running an over-square setting of.....
memory says.....about 29" MAP and 1900RPM.
His comment was that only Lycoming engines could do that.
Thanks for the memories.
Guess who the surprise guest speaker was.
Steen

Now THAT I''ll have to try!